Study on Friesian Herds Raised in Egypt and Germany – II. Genetic and phenotypic trends in estimated transmitting ability

Abstract. Original data consisted of 774 first lactation records of daughters of 124 sires of Friesian herds in Egypt and 9219 first lactation records of daughters of 679 sires of Friesian herds in Germany used to estimate genetic and phenotypic trends of initial milk yield in 70 days (IMY), 305-day milk yield (305-dMY), lactation period (LP) and calving interval (CI). Sire component of variance was consistently about 9.88%, 10.75%, 4.63% and 5.03% for IMY, 305-dMY, LP and CI, respectively of the total Variation in Friesian cows in Egypt and about 16.69%, 16.69%, 3.63% and 4.37%, for IMY, 305-dMY, LP and CI, respectively of the total Variation in Friesian cows in Germany. Annual genetic change was 29.98 kg, 112.99 kg, −0.92 d and 1.78 d for IMY, 305-dMY, LP and CI, respectively for Friesian cows in Egypt and was 70.41 kg, 200.38 kg, 0.12 d and −1.05 d for IMY, 305-dMY, LP and CI, respectively for Friesian cows in Germany. Annual phenotypic trend was 13.83 kg, 48.00 kg, −1.66 d and −1.82 d for IMY, 305-dMY, LP and CI, respectively for Friesian cows in Egypt and was 21.00 kg, 104.00 kg, 0.17 d and 0.78 d for IMY, 305-dMY, LP and CI, respectively for Friesian cows in Germany. The present results show that sires used in the later years were of superior genetic value than those used in the earlier years.